1. Field of the Invention
The invention relates to a switch, more particularly to a rolling-ball switch that is mounted on a circuit board for changing between OFF and ON states.
2. Description of the Related Art
Referring to FIGS. 1 to 3, a conventional switch 10, as disclosed by the applicant in Taiwanese Patent No. 155965, includes a housing, a conductive ball 12, and four terminal rods 14.
The housing includes a bottom seat 13 and a cover body 11. The bottom seat 13 is made of plastic, and has top and bottom surfaces, and four spaced-apart insert holes 131 extending through the top and bottom surfaces. Each of the insert holes 131 is defined by four interconnected hole walls 132. The cover body 11 is made of plastic, and has a top wall 111, and four interconnected side walls 112 extending downwardly from a peripheral end of the top wall 111. The top wall 111 and the side walls 112 cooperatively define a chamber 113, and a bottom opening 114 opposite to the top wall
The bottom seat 13 is inserted into the chamber 113 after the conductive ball 12 is disposed in the latter so as to close the bottom opening 114 and thereby confine the conductive ball 12 within the chamber 113.
The terminal rods 14 are inserted respectively and interferentially into the insert holes 131 by a jig (not shown) so as to position the terminal rods 14 in the respective insert holes 131. Each terminal rod 14 has an inner end 141 located within the chamber 113, an outer end 142 located outwardly of the bottom seat 13, and four interconnected side surfaces 143 that interconnect the inner and outer ends 141, 142.
In use, the outer ends 142 of the terminal rods 14 are inserted respectively into through holes 21 in a circuit board 20, after which the terminal rods 14 are soldered to the circuit board 20, thereby mounting and positioning the switch 10 on the circuit board 20. The switch 10 is tilted or turned so as to shift from an OFF state to an ON state, and vice versa.
Although the aforementioned conventional switch 10 can achieve its intended purpose, it has the following drawbacks:
1. Because the switch 10 can have various applications, the switch 10 is not always mounted uprightly on the circuit board 20, as shown in FIG. 2. For example, the switch 10 can be mounted parallel to the circuit board 20, as shown in FIG. 3. In the latter case, a manufacturer has to bend the terminal rods 14 first, so that the user, after purchasing the switch 10, can directly insert and solder the terminal rods 14 to the circuit board 20. Further, the switch 10 must have bendable terminal rods 14 in order to allow such re-shaping thereof. Hence, the conventional switch 10 may have a very complicated manufacturing process in the case where such bending is required, and has a high production cost due to the fact that high-cost bendable material is required for the terminal rods 14.
2. Because each terminal rod 14 is configured as a single individual body, when the terminal rods 14 are inserted respectively into the insert holes 131, it is difficult to control the lengths of the inner ends 141 of the terminal rods 14 that extend into the chamber 113. Hence, difficulties are encountered with respect to controlling the quality of the conventional switch 10.
3. Since the side surfaces 143 of the terminal rods 14 are smooth, connections between the side surfaces 143 and the hole walls 132 of the insert holes 131 are weak and unstable.